WATCH: Judge hears arguments: Can Quebec decide to unilaterally separate from Canada?

After 17 years of legal and administrative delays,  a judge is now hearing arguments about the constitutionality of Bill 99 that asserts Quebec's right to unilaterally separate from Canada after a referendum victory.

Bill 99 was Quebec's response to the federal government's Clarity Act spelling out the conditions for Quebec independence.

The former leader of the now-defunct Equality Party Keith Henderson filed a legal challenge to Bill 99, arguing it was unconstitutional. Henderson contested that Quebec would have carte blanche to secede from Canada and with a 50% plus one majority referendum vote.

The Attorney General of Quebec is arguing that this is a hypothetical situation.

Henderson said the issue is just as relevant now.

"Why worry? Why worry? Because things change. Because this isn't for today, this is for the future. This is a big issue," said Henderson.

"If the PQ comes back to power and decide, Well, we're going to start the music all over again - witness Scotland - it's not impossible. Then we have...somebody's taken the law to court and done the homework and set the rules so that's what this is all about. It's for the future."

Henderson filed his motion in 2001 but the case was held up by legal and administrative delays.

Besides Henderson and the Attorney General of Quebec, lawyers for the Attorney General of Canada and the nationalist Société St-Jean Baptiste are expected to present arguments in roles of intervenor status.

The case is scheduled to last a week before judge Claude Dallaire.